Oil supply system for engine equipped with cvvt

ABSTRACT

The present disclosure provides an oil supply system for an engine equipped with a Continuous Variable Valve Timing (CVVT) that includes: a camshaft having an internal space; and a lock pin that is unlocked from a lock pin hole by oil supplied from the internal space of the camshaft through an oil channel formed in a CVVT.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefit of Korean Patent Application No. 10-2015-0091597, filed Jun. 26, 2015, which is incorporated herein by reference in its entirety.

FIELD

The present disclosure relates to an oil supply system for an engine, and more particularly, to an oil supply system for an engine that is equipped with a CVVT for supplying hydraulic pressure.

BACKGROUND

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

A camshaft that is a rotary member and a Continuous Variable Valve Timing (CVVT) are parts in a cylinder head of an engine requiring oil. When a CVVT is operated not hydraulically, but electrically, an oil supply structure using an Oil Control Valve (OCV) for supplying hydraulic pressure for unlocking a locking pin for self-lock is used.

Referring to FIG. 1, a CVVT 60 of the related art has an oil channel 20 independent from a supply path of oil supplied to a camshaft (not shown). That is, when oil is supplied to the oil channel 20 through an oil hole 51 of the OCV 50 and hydraulic pressure is supplied into the CVVT 60, a lock pin 30 is separated from a lock pin hole 31.

Accordingly, in order to achieve this operation, it is required to add one oil journal groove in the camshaft (not shown) and an oil supply hole for supplying oil from a cylinder head to the camshaft by a process of additionally machining the head and the camshaft, so the entire process is complicated and additional cost is required, thereby increasing the manufacturing cost.

SUMMARY

The present disclosure proposes an oil supply system for an engine that is equipped with a CVVT that can reduce an investment cost and a manufacturing cost by changing the configuration for supplying oil for controlling a lock pin in an intermediate phase CVVT using a separate OCV.

According to one aspect of the present disclosure, there is provided an oil supply system for an engine equipped with a CVVT that includes: a camshaft having an internal space; and a lock pin that is unlocked from a lock pin hole by oil supplied from the internal space of the camshaft through an oil channel formed in a CVVT.

The internal space of the camshaft may extend and communicate with the CVVT, thereby forming an oil channel reaching the lock pin.

An OCV may be disposed between the camshaft and the CVVT, the internal space of the camshaft, the OCV, and the CVVT may communicate with each other by one oil channel.

A bolt valve having an oil passage communicating with the camshaft and the OCV and supplying oil flowing inside to the lock pin through an oil hole formed in a side may be disposed in the oil channel.

The outer diameter of the bolt valve may be the same as the inner diameter of the oil channel.

A spool may be disposed in the bolt valve, and when a current is supplied to an electronic actuator, the spool may be operated, oil supplied from the camshaft may be supplied to the lock pin through a gap between an outer side of the bolt valve and the spool, and the lock pin may be unlocked.

According to the oil supply system for an engine that is equipped with a CVVT, even in an intermediate phase CVVT using a separate OCV, there may be no need for a specific passage to supply oil from an oil line provided for lubricating a camshaft, so the configuration is simple. Further, it can be used without changing existing manufacturing lines, so engines can be easily manufactured and the manufacturing cost can be reduced by decreasing the costs for machining a camshaft and a head.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

FIG. 1 illustrates a view showing an oil supply system for an engine that is equipped with a CVVT in the related art;

FIG. 2 illustrates an oil supply system for an engine that is equipped with a CVVT according to an embodiment of the present disclosure;

FIG. 3 illustrates a view showing an oil supply system for an engine that is equipped with a CVVT according to another embodiment;

FIG. 4 illustrates a view showing operation of the CVVT shown in FIG. 3; and

FIG. 5 is a view showing locking of a lock pin of the CVVT shown in FIG. 3.

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

FIG. 2 illustrates an oil supply system for an engine that is equipped with a Continuous Variable Valve Timing (CVVT) according to an embodiment of the present disclosure and FIG. 3 is a view showing an oil supply system for an engine that is equipped with a CVVT according to another embodiment. FIG. 4 is a view showing operation of the CVVT 600 shown in FIG. 3 and FIG. 5 is a view showing locking of a lock pin 300 of the CVVT 600 shown in FIG. 3.

Conventional hydraulic CVVTs need oil supply for its operation, so that the hydraulic CVVTs perform self-lock using the oil supplied. Unlike the conventional CVVTs, the present disclosure relates to a CVVT 600 equipped with the electronic actuator 900 and may not need hydraulic pressure for its own operation. Instead, the CVVT 600 may use oil supply only for self-lock. Accordingly, in the following configuration, oil for self-lock of the CVVT 600 using the electronic actuator 900 is supplied through an oil line for lubricating a camshaft 100.

Referring to FIG. 2, an oil supply system for an engine that is equipped with a CVVT according to an embodiment of the present disclosure includes: a camshaft 100 that has an internal space 110 therein; and a lock pin 300 configured to be unlocked from a lock pin hole 310 by oil supplied from the internal space 110 of the camshaft 100 through an oil channel 200 formed in a CVVT 600. Accordingly, the internal space 110 extends and communicates with the CVVT 600, thereby forming the oil channel 200 reaching the lock pin 300. Further, an OCV 500 may be disposed between the camshaft 100 and the CVVT 600, and the oil channel 200 is formed by the internal space 110 of the camshaft 100, the OCV 500, and the CVVT 600, so hydraulic pressure for unlocking the lock pin 300 can be achieved from oil supplied from a cylinder block (not shown) through the internal space 110 of the camshaft 100.

With this arrangement, oil from a cylinder block to lubricate the camshaft 100 is utilized for unlocking the lock pin 300 of the CVVT 600, and in particular is supplied to the lock pin 300 through the oil channel 200 in the CVVT 600 from the internal space 110 of the camshaft 100. Accordingly, unlike the related art in which the oil channel 200 for controlling the lock pin 300 of the intermediate phase CVVT 600 is separately provided, the present disclosure provides a simple oil supply system and thus reduces the working processes, so it is possible to reduce the costs for machining the camshaft 100 and the head.

Referring to FIGS. 3 to 5, an oil supply system for an engine that is equipped with a CVVT according to another embodiment of the present disclosure includes: a camshaft 100 that has a space 110 therein; and a lock pin 300 configured to be unlocked from a lock pin hole 310 by oil supplied from the space 110 of the camshaft 100 through an oil channel 200 formed in a CVVT 600. Further, there is provided a bolt valve 700 that has an oil passage 710 (FIG. 4) communicating with the camshaft 100 and the OCV 500 in the oil channel 200 and supplies oil flowing inside to the lock pin 300 through an oil hole 730 formed in a side. The outer diameter of the bolt valve 700 is the same as the inner diameter of the oil channel 200, so oil is supplied to the lock pin 300 after flowing into the oil passage 710 of the bolt valve 700 from the internal space 110 of the camshaft 100.

Similar to the previous embodiment, the internal space 110 of the camshaft 100 extends and communicates with the CVVT 600, thereby forming the oil channel 200 reaching the lock pin 300. Further, the OCV 500 and the bolt valve 700 are disposed between the camshaft 100 and the CVVT 600. Accordingly, the internal space 110 of the camshaft 100, the OCV 500, the CVVT 600, and the bolt valve 700 may communicate with each other by one oil channel 200. Further, a spool 750 is disposed in the bolt valve 700, so when a current is supplied to the actuator 900, the spool 750 is operated and oil supplied from the camshaft 100 passes through the OCV 500 and is supplied to the lock pin 300 through the gap between the bolt valve 700 and the spool 750. Accordingly, hydraulic pressure is applied to the lock pin 300 and the lock pin 300 is separated from a lock pin hole 310.

This configuration is described in more detail with reference to the drawings. FIG. 4 is a view showing operation of the CVVT 600 shown in FIG. 3. Referring to FIG. 4, first, when a current is supplied to the electronic actuator 900, the spool 750 in the bolt valve 700 is operated, so a gap allowing oil to flow is formed between the outer side of the bolt valve 700 and the spool 750. Accordingly, oil supplied from a cylinder block passes through the internal space 110 of the camshaft 100 and is supplied to the lock pin 300 through the gap between the outer side of the bolt valve 700 and the spool 750, so the lock pin 300 is separated from the lock pin hole 310 by the hydraulic pressure of the oil. Further, independently from this configuration oil is supplied to an advancing chamber and a retarding chamber of the CVVT 600 from the OCV 500, so the CVVT 600 is operated.

On other hand, operation for locking the lock pin 300 after the operation of the CVVT 600 is described with reference to FIG. 5. Referring to FIG. 5, when the current applied to the electronic actuator 900 is stopped, the spool 750 is returned by a spring in the bolt valve 700. Accordingly, the gap between the outer side of the bolt valve 700 and the spool 750 is blocked, so the oil supplied to the lock pin 300 is stopped and the lock pin 300 is inserted and locked into the lock pin hole 310 by elastic force of an elastic member on the lock pin 300.

According to the oil supply system for an engine that is equipped with a CVVT, even in an intermediate phase CVVT using a separate OCV, there may be no need for a specific passage to supply oil through an oil line provided for lubricating a camshaft, so the configuration is simple. Further, it can be used without changing existing manufacturing lines, so engines can be easily manufactured and the manufacturing cost can be reduced by decreasing the costs for machining a camshaft and a head.

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the present disclosure as disclosed in the accompanying claims. 

What is claimed is:
 1. An oil supply system for an engine equipped with a Continuous Variable Valve Timing (CVVT), comprising: a camshaft comprising an internal space; and a lock pin configured to be unlocked from a lock pin hole by an oil supplied from an internal space of the camshaft through an oil channel formed in the CVVT.
 2. The oil supply system according to claim 1, wherein the internal space of the camshaft extends and communicates with the CVVT, thereby forming an oil channel reaching the lock pin.
 3. The oil supply system according to claim 1, wherein an Oil Control Valve (OCV) is disposed between the camshaft and the CVVT, and the internal space of the camshaft, the OCV, and the CVVT communicate with each other by a single oil channel.
 4. The oil supply system according to claim 1, wherein a bolt valve comprising an oil passage configured to communicate with the camshaft and the OCV and configured to supply an oil flowing inside to the lock pin through an oil hole formed in a side is disposed in the oil channel.
 5. The oil supply system according to claim 4, wherein an outer diameter of the bolt valve is the same as an inner diameter of the oil channel.
 6. The oil supply system according to claim 4, wherein a spool is disposed in the bolt valve, and when a current is supplied to an electronic actuator, the spool is operated, oil supplied from the camshaft is supplied to the lock pin through a gap between an outer side of the bolt valve and the spool, and the lock pin is unlocked. 